Every weekday, a CNNHealth expert doctor answers a viewer question. On Wednesdays, it’s Dr. Otis Brawley, chief medical officer at the American Cancer Society. Asked by Faye from Farmville, North Carolina How long does it take.

Compression tights are touted as enabling athletes to run faster and farther, while reducing injuries, but a new Nike-funded study—one that appears to have backfired on the clothing manufacturer—suggests these trendy items don’t work as.

The average young American now spends practically every waking minute — except for the time in school — using a smart phone, computer, television or other electronic device, according to a new study from the Kaiser Family.